The present invention concerns a method for making safety labels to protect products, and labels obtained by this method.
The development of reprographly techniques is making it increasingly easy to copy or falsify documents, particularly fiduciary papers, bank notes, stamps, etc.
Verifying the authenticity of a product consists in verifying the authentication and security elements carried on the product. These authentication and security elements are generally composed of markings integrated in the product that are only able to be read by a detector. Verification may consist in comparing the nattier, shape, and position of authentication and security elements with model authentication and security elements inaccessibly or inviolably stored in the monitory of the device effecting the verification. This is the cease concerning blank notes. These products incorporate marking and verification elements integrated in the blank notes that are generally able to be read with a light beam of specific wavelength, preferably within the non-visible light range.
But refinement of the means of analysis available on the market is making it increasingly difficult to take effective countermeasures, ie means preventing unauthorized persons from being able to analyses and know clearly the marking and authentication and security elements and consequently from using this knowledge to falsify products, ie authentication and security elements which, when read by a detector, are interpreted by the latter as corresponding to authentication and security elements that are true and not false.
In the field of security for authentication and security means, it is certainly possible, through important means being put in place, to make an object or product difficult to falsify or, at least, to make such falsification so difficult that it is no longer of any interest.
Much the same also applies to products made or used in very large number, such as eg bank notes or fiduciary papers. For the latter, the production cost and particularly the cost of means of security are a determining element.
In other words, for such products, the means of security or protection against falsifications are necessarily integrated in an industrial process and must be compatible with such implementation conditions. They must be related to a usual production cost that is not in any way excessive and must stand in marked contrast to the one-off production field with prohibitive costs.
The different technico-economic imperatives limit the opportunities for protection of available industrial means. The printing of bank notes, fiduciary papers, and stamps thus currently uses conventional printing techniques whose limits set on accurate printing and positioning of authentication and security elements are those of conventional printing techniques.
The integration of authentication and security elements in the form of holograms and means composed of optically variable and diffracting images faces the same physical error limits and thereby fails to provide the necessary safety.
These means composed optically variable and diffracting images called DOVID arc characterised by different images that appear depending on the angle at which they arc observed, being obtained by the angulation of microreliefs produced during film stamping by the die.
The purpose of the present invention is to develop a method enabling the safety of products against falsifications to be considerably increased by making these falsifications extremely difficult.
To this end, the invention concerns a method characterised in that
a base deposit is made on a film,
a label shape is defined,
a printing window is made preferably according to the label shape as an engraved surface with cells bordered by a stripe forming the window outline,
the punting window is printed with marking preferably on the film base deposit with a passivation coating,
the window is developed by a physico-chemical operation,
the label is detached and recovered.
Through the authentication and security elements comprising the label being accurately produced and positioned, it is possible to identify an authentic product, ie integrating an authentic label, with the safety increased by several orders of magnitude.
The label is used in the state where it can he transferred to the surface and/or core of the material for authentication and security purposes.
The accuracy with which the label is produced also makes it possible to increase the complexity of the shape, or outline, or inclusions, or reserves, our else placement of the authentication and security elements, with the latter moreover making it possible to integrate, in a manner very difficult to reveal, authentication and security elements that can only be revealed or perceived under conditions compatible with the accuracy of production.
The printing cylinder, preferably of photogravure type, is engraved with an image incorporating engraved zones whose outlines are surrounded by a stripe to permit high-resolution printing without any indentation.
The production accuracy possible according to the invention this makes it possible to increase beyond suspicion the detection accuracy and conversely the accuracy or downsizing of the authentication and security elements, whereas this accuracy has so far been very largely limited by the error risk associated with the inaccuracy of production.
This accuracy makes it possible to camouflage more easily multiple authentication and security elements that are imperceptible under usual conditions of analysis through being undetectable and situated very much beyond the limits of errors currently able to be envisaged.
Finally, this very great accuracy makes it possible to multiply the number of marking elements and thereby to increase safety against falsifications.
This production accuracy is largely due to the quality of the stripe, which has a thickness ranging between 2 and 50 xcexcm depending on the material to be deposited, preferably 20 xcexcm.
And in particular, the stripe has a distance from the cells ranging between 5 and 50 xcexcm, preferably 20 xcexcm.
The window defining the label has an outline combining concave and/or convex lines, curves, and/or straight lines. The window may have a uniformly convex outline or an outline with alternating concave and convex curves. This outline may be formed from segments of curves and/or segments of straight lines and bears letterings and negative and positive embellishments.
The complexity of the window is associated with the complexity it is desired to give the label to make its falsification difficult or, in the case of an integrated circuit, to adapt to the type of circuit.
According to another characteristic of the invention, the window having an outline is positioned laterally in relation to the reading of a guide channel located on the coated strip and positioned longitudinally in relation to the reading of a spot or marker whose signal allows positioning control of the window on the pattern(s) carried by the coated strip, with the whole set having a tolerance between 0.1 mm and 0.5 mm, preferably 0.2 mm.
According to the invention, the method for application of a window by marking and physicochemical treatment may be repeated a specific number of times depending on the layers to be produced with one window being defined for each layer. The operations performed at the level of each layer may also be different. In one case, there may be a physico-chemical operation working to remove material. In another case, the operation may consist in an application of material (eg by electrolysis with consumable electrodes). In a third case, removal and deposition arc simultaneous. The window is also not necessarily the area delimited by a closed outline. The window may equally be the area situated outside a closed outline with a more or less complex shape.
Finally, inside a window, it is possible to have complementary or auxiliary windows each time defining the zones of more reduced areas.
In most cases, the substrate is a film, and the base deposit is a metal deposit. However, other materials may be envisaged.
In a particularly advantageous manner, the base deposit comprises a hologram notably bearing a metal base deposit. Marking of holograms and means composed of optically variable and diffracting images or equivalent elements on the film is advantageously accomplished by marking elements intended to interact with detectors equipping the installation to allow accurate positioning and marking for positioning of the windows.
The base deposit may also comprise a base, particularly a patterned base.
These different means make it possible to produce extremely complex and highly accurate structures depending on the results to be obtained, such as eg the production of integrated circuits or elements for protection against falsifications. In the description, the term xe2x80x9clabelxe2x80x9d will he used in a general way to embrace these different embodiments.
According to another characteristic, the printed passivation coating is of cellulose and/or metal and/or plastic and/or vacuum metallised plastic type.
The printed passivation coating is alternatively insoluble and composed of a polymer, preferably a nitrocellulose polymer, incorporating a charge of variable type depending on the end use of the printed strip, particularly conductive or insulating pigments or charges such as metal oxides preferably titanium, iron, boron, nickel, chromium, carbon, silicon, etc oxides used individually or in combinations.
According to another characteristic, the printed passivation coating is soluble and composed of a polymer, preferably a polyvinyl alcohol polymer or any other polymer that is water-soluble but insensitive to the aqueous solution for window development.
The invention also concerns an installation for making safety labels, for implementation of the method as described above, and which incorporates a feeding station supplying a strip provided with a coating, a printing station with a photogravure printing set for application of printing windows on the strip, preferably photogravure, followed on its downstream side by an electrolysis station for carrying out electrolysis on the strip, a washing installation for cleaning the strip surface, a drying station, an inspection station, and a coiling station.
It thus incorporates a set of machines and equipment comprising a treatment zone provided with insoluble electrodes immersed in an electrolyte under a current allowing rapid corrosion of the non-printed zones of a metal or metallised preprinted film which skims the electrolyte surface as it passes.
The aqueous solution for window development is composed of a salt with its base or acid associated, such as NaOH and NaCl, at a concentration ranging between 5 and 150 g/l, preferably 100 g/l.
According to another characteristic, the window development solution is an electrolyte with its base or acid associated, such as NaOH NaCl, and CuCl2, at a concentration ranging between 15 and 150 g/l, preferably 100 g/l.
The temperature of the electrolyte advantageously ranges between 5 and 90xc2x0 C., preferably being 40xc2x0 C.
The electric voltage on the electrode terminals is continuous, ranging between 2 V and 21 V, preferably being 6 V.
In the electrolysis station, the electrode is a rod having a section with a geometry favoring the concentration of current flows towards the metal film to be corroded, being of triangular shape with one of the triangle vertices being directed towards the film.
The electrode material is a material insoluble in the aqueous development solution even under an electric current, such as titanium.
According to another characteristic, the installation is composed of a set of machines and equipment comprising a treatment zone provided with soluble electrodes immersed in an electrolyte under a current allowing rapid deposition on a preprinted window film.
In this installation, the development solution is an electrolyte with its base or acid associated, such as CuCl2 and HCl, at a concentration ranging between 5 and 150 g/l, preferably 100 g/l
It is also of interest that the current on the electrode terminals is a direct current applied at a voltage ranging between 5 and 30 V, preferably 6 V.
According to an advantageous characteristic, the section of the electrode rod has a geometry favoring the dissolution of electrode metal, accordingly a maximum surface in contact with the electrolyte. ie eg a circular section.
In this case, the electrode material is a material that is soluble in the electrolyte, such as copper to deposit a copper film.
The anodes and cathodes are advantageously immersed in parallel in relation to each other, being separated by insulating partitions perpendicularly to uncoiling of the film, in the window development solution at a distance of several mm, preferably more than 1 mm, which skims the surface of the electrolyte without being immersed therein.
According to the invention, the section of the rod electrode has a geometry favoring the concentration of current flows towards the metal film to be corroded and favoring its dissolution in the electrolyte, preferably a teardrop shape whose tip is directed towards the film.
According to another characteristic, the installation is composed of a set of machines and equipment comprising a washing zone provided with drying cycles between steel cylinders and polymer cylinders to limit the drives and to facilitate drying by evaporation of washing liquid in such a way that the soluble passivation coating is dissolved and that the treated film is dry and free from any trace of electrolyte incompatible with its end use.
According to another characteristic, the installation is composed of a set of machines and equipment arranged in line to provide a separated multi-station machine to ensure that printing is separated from the other operations themselves arranged in a second machine.
According to another characteristic, the installation is composed of a set of machines and equipment comprising two inspection zones between printing and treatment and a third after drying, being equipped with probes for continuous detection of the conductivity of the different zones and with video cameras to verify that the resolution in different stages of the operations is being met.
The invention also concerns the products obtained by the method and installation.
According to the invention, the product thus derives from a film incorporating multiple layers of insulating and conductive materials or insulating and metallic materials able to be used in the printing of fiduciary materials in order to make them secure.
According to another characteristic, it is intended to produce holograms and means composed of optically variable and diffracting images, images optically variable by diffraction, or the like for security purposes that are marked and demetallised and where the thickness of the passivation coating ranges between 0.5 and 8 xcexcm, preferably 1 xcexcm, to make it possible to overcome the irregularities of the substrate onto which the said patterns arc transferred.
According to the invention, it is intended to produce a film incorporating multiple layers of insulating and conductive materials or insulating and metallic materials able to he used in the printing of materials destined for the electronic industry.
The product is intended for the electronic industry where the multiple layers have a thickness ranging between 0.05 xcexcm and 5 xcexcm, preferably 1 xcexcm, to limit the final thicknesses, but moreover to produce high-precision passivation coatings with a thickness ranging between 0.05 xcexcm and 5 xcexcm, preferably 1 xcexcm.
The product is further intended for the electronic industry where the metal layers have a thickness ranging between 5 xc3x85 and 600 xc3x85, preferably 50 xc3x85.
According to the invention, the product is composed of patterns whose outlines arc smoothed and have no indentation.
The product is composed of patterns with a resolution ranging between 10 xcexcm and 100 xcexcm, preferably 50 xcexcm either lines or chequered elements with a minimum thickness and distance ranging between 10 xcexcm and 100 xcexcm, preferably 50 xcexcm.
The patterns are metallic patterns.
The product is also composed of a polymer film coated with metallic holograms, DOVID, or the like that are marked, demetallised, and cut out in the paper during their production in order to make the patterns visible by either transparency or reflection.
According to another characteristic, the product is composed of a polymer film coated with metallised detachable layer incorporating hologram is and/or DOVID o r the like that are marked, demetallised, and coated with different layers necessary for its continuous transfer (stripe) and/or marked (patch) on the final paper.
According to another characteristc, the product is composed of a metallised coated or uncoated polymer film incorporating holograms and/or DOVID or the lie that are marked, demetallised, laminated with another polymer, coated, cut out or not cut out and which is characterised by destruction of its images as soon as an attempt is made to detach it from its final substrate comprising a detachable film.
The same products may be made without holograms, DOVID, or the like.